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Redox-responsive targeted gelatin nanoparticles for delivery of combination wt-p53 expressing plasmid DNA and gemcitabine in the treatment of pancreatic cancer.

Xu J, Singh A, Amiji MM - BMC Cancer (2014)

Bottom Line: Efficacy studies demonstrate an improved in vivo targeting efficiency resulting in increased transfection efficiency and tumor growth suppression.Gene/drug combination treatment significantly improves the therapeutic performance of the delivery system compared to the gene or drug alone treated groups.Anti-tumor activity of the thiolated gelatin loaded wt-p53 plasmid or gemcitabine-based therapy was attributed to their ability to induce cell apoptosis, which was confirmed by a marked increase in mRNA level of proapoptotic transcription factors, as well as, protein apoptotic biomarker expression and significant decrease in the anti-apoptotic transcription factors.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Pharmaceutical Sciences, School of Pharmacy, Northeastern University, 360 Huntington Avenue, Boston, MA 02115, USA. m.amiji@neu.edu.

ABSTRACT

Background: Pancreatic adenocarcinoma is one of the most dreaded cancers with very low survival rate and poor prognosis to the existing frontline chemotherapeutic drugs. Gene therapy in combination with a cytotoxic agent could be a promising approach to circumvent the limitations of previously attempted therapeutic interventions.

Method: We have developed a redox-responsive thiolated gelatin based nanoparticle system that efficiently delivers its payload in the presence of glutathione-mediated reducing intra-cellular environment and could be successfully used for site-specific wt-p53 expressing plasmid DNA as well as gemcitabine delivery by targeting epidermal growth factor receptor (EGFR). Efficacy studies were performed in subcutaneous human adenocarcinoma bearing SCID beige mice along with molecular level p53 plasmid and apoptotic marker expression by PCR and western blot for all study groups.

Results: Efficacy studies demonstrate an improved in vivo targeting efficiency resulting in increased transfection efficiency and tumor growth suppression. In all the treatment groups, the targeted nanoparticles showed better anti-tumor activity than their non-targeted as well as non-encapsulated, naked therapeutic agent counterparts (50.1, 61.7 and 77.3% tumor regression by p53 plasmid alone, gemcitabine alone and in combination respectively). Molecular analysis revealed a higher mRNA expression of transfected p53 gene, its corresponding protein and that the tumor cell death in all treatment groups was due to the induction of apoptotic pathways.

Conclusions: Gene/drug combination treatment significantly improves the therapeutic performance of the delivery system compared to the gene or drug alone treated groups. Anti-tumor activity of the thiolated gelatin loaded wt-p53 plasmid or gemcitabine-based therapy was attributed to their ability to induce cell apoptosis, which was confirmed by a marked increase in mRNA level of proapoptotic transcription factors, as well as, protein apoptotic biomarker expression and significant decrease in the anti-apoptotic transcription factors.

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In vivo anti-tumor activity of wt-p53 loaded gelatin nanoparticles. (a) Volume change as a function of time showing 27.9, 38.3* and 50.1%** reduction in tumor growth on day 33 for wt-p53 loaded SH-Gel, SH-Gel-PEG and SH-Gel-PEG-peptide nanoparticle treated tumor respectively. (b) Tumor weights on day 7, 18 and 33. Results are presented as mean ± SD (n = 3 for day 7 and 18; n = 6 for day 33) (* p < 0.05; ** p < 0.01; *** p < 0.001).
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Figure 1: In vivo anti-tumor activity of wt-p53 loaded gelatin nanoparticles. (a) Volume change as a function of time showing 27.9, 38.3* and 50.1%** reduction in tumor growth on day 33 for wt-p53 loaded SH-Gel, SH-Gel-PEG and SH-Gel-PEG-peptide nanoparticle treated tumor respectively. (b) Tumor weights on day 7, 18 and 33. Results are presented as mean ± SD (n = 3 for day 7 and 18; n = 6 for day 33) (* p < 0.05; ** p < 0.01; *** p < 0.001).

Mentions: Subcutaneous human pancreatic adenocarcinoma (Panc-1) bearing female SCID beige mice (n = 12) were intravenously dosed with wt-p53 naked and gelatin encapsulated plasmid (20 μg/dose) at day 0, 2 and 4 and tumor volume was monitored as a function of time till the end of the study (day 33). Also, 3 mice from each treatment group were sacrificed at day 7 and 18 to measure tumor weight, gene expression and analysis of downstream apoptotic markers. Plasmid loaded SH-Gel-PEG-peptide and SH-Gel-PEG nanoparticles produced tumor growth inhibition of 50.1% (p < 0.01) and 38.3% (p < 0.05) respectively compared to control group, confirming that wt-p53 gene administration show tumor growth suppression (Figure 1a). On the contrary, naked as well as SH-Gel loaded plasmid shows little anti-tumor activity suggesting that targeting and long-circulating characteristics are essential for enhanced intra-tumor localization of the nanoparticles. Weight of the tumors obtained from mice of different treated groups after day 7, 18 and 33 (Figure 1b) do not show remarkable difference at day 7 and 18 but were found to be significantly decreased compared to control at day 33.


Redox-responsive targeted gelatin nanoparticles for delivery of combination wt-p53 expressing plasmid DNA and gemcitabine in the treatment of pancreatic cancer.

Xu J, Singh A, Amiji MM - BMC Cancer (2014)

In vivo anti-tumor activity of wt-p53 loaded gelatin nanoparticles. (a) Volume change as a function of time showing 27.9, 38.3* and 50.1%** reduction in tumor growth on day 33 for wt-p53 loaded SH-Gel, SH-Gel-PEG and SH-Gel-PEG-peptide nanoparticle treated tumor respectively. (b) Tumor weights on day 7, 18 and 33. Results are presented as mean ± SD (n = 3 for day 7 and 18; n = 6 for day 33) (* p < 0.05; ** p < 0.01; *** p < 0.001).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3927583&req=5

Figure 1: In vivo anti-tumor activity of wt-p53 loaded gelatin nanoparticles. (a) Volume change as a function of time showing 27.9, 38.3* and 50.1%** reduction in tumor growth on day 33 for wt-p53 loaded SH-Gel, SH-Gel-PEG and SH-Gel-PEG-peptide nanoparticle treated tumor respectively. (b) Tumor weights on day 7, 18 and 33. Results are presented as mean ± SD (n = 3 for day 7 and 18; n = 6 for day 33) (* p < 0.05; ** p < 0.01; *** p < 0.001).
Mentions: Subcutaneous human pancreatic adenocarcinoma (Panc-1) bearing female SCID beige mice (n = 12) were intravenously dosed with wt-p53 naked and gelatin encapsulated plasmid (20 μg/dose) at day 0, 2 and 4 and tumor volume was monitored as a function of time till the end of the study (day 33). Also, 3 mice from each treatment group were sacrificed at day 7 and 18 to measure tumor weight, gene expression and analysis of downstream apoptotic markers. Plasmid loaded SH-Gel-PEG-peptide and SH-Gel-PEG nanoparticles produced tumor growth inhibition of 50.1% (p < 0.01) and 38.3% (p < 0.05) respectively compared to control group, confirming that wt-p53 gene administration show tumor growth suppression (Figure 1a). On the contrary, naked as well as SH-Gel loaded plasmid shows little anti-tumor activity suggesting that targeting and long-circulating characteristics are essential for enhanced intra-tumor localization of the nanoparticles. Weight of the tumors obtained from mice of different treated groups after day 7, 18 and 33 (Figure 1b) do not show remarkable difference at day 7 and 18 but were found to be significantly decreased compared to control at day 33.

Bottom Line: Efficacy studies demonstrate an improved in vivo targeting efficiency resulting in increased transfection efficiency and tumor growth suppression.Gene/drug combination treatment significantly improves the therapeutic performance of the delivery system compared to the gene or drug alone treated groups.Anti-tumor activity of the thiolated gelatin loaded wt-p53 plasmid or gemcitabine-based therapy was attributed to their ability to induce cell apoptosis, which was confirmed by a marked increase in mRNA level of proapoptotic transcription factors, as well as, protein apoptotic biomarker expression and significant decrease in the anti-apoptotic transcription factors.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Pharmaceutical Sciences, School of Pharmacy, Northeastern University, 360 Huntington Avenue, Boston, MA 02115, USA. m.amiji@neu.edu.

ABSTRACT

Background: Pancreatic adenocarcinoma is one of the most dreaded cancers with very low survival rate and poor prognosis to the existing frontline chemotherapeutic drugs. Gene therapy in combination with a cytotoxic agent could be a promising approach to circumvent the limitations of previously attempted therapeutic interventions.

Method: We have developed a redox-responsive thiolated gelatin based nanoparticle system that efficiently delivers its payload in the presence of glutathione-mediated reducing intra-cellular environment and could be successfully used for site-specific wt-p53 expressing plasmid DNA as well as gemcitabine delivery by targeting epidermal growth factor receptor (EGFR). Efficacy studies were performed in subcutaneous human adenocarcinoma bearing SCID beige mice along with molecular level p53 plasmid and apoptotic marker expression by PCR and western blot for all study groups.

Results: Efficacy studies demonstrate an improved in vivo targeting efficiency resulting in increased transfection efficiency and tumor growth suppression. In all the treatment groups, the targeted nanoparticles showed better anti-tumor activity than their non-targeted as well as non-encapsulated, naked therapeutic agent counterparts (50.1, 61.7 and 77.3% tumor regression by p53 plasmid alone, gemcitabine alone and in combination respectively). Molecular analysis revealed a higher mRNA expression of transfected p53 gene, its corresponding protein and that the tumor cell death in all treatment groups was due to the induction of apoptotic pathways.

Conclusions: Gene/drug combination treatment significantly improves the therapeutic performance of the delivery system compared to the gene or drug alone treated groups. Anti-tumor activity of the thiolated gelatin loaded wt-p53 plasmid or gemcitabine-based therapy was attributed to their ability to induce cell apoptosis, which was confirmed by a marked increase in mRNA level of proapoptotic transcription factors, as well as, protein apoptotic biomarker expression and significant decrease in the anti-apoptotic transcription factors.

Show MeSH
Related in: MedlinePlus